Policies for transition towards post-carbon cities of built environment are being developed at the building stock scale, but estimating the energy performance remains a challenge, due to the great computational efforts required by disaggregated energy modeling. This research aims to provide an innovative methodology for conducting energy assessments at the district scale by integrating data from aerial thermography with Energy Performance Certificates through a Geographic Information System. A thermographic orthophoto is used to obtain temperature data for roofs, thus deriving heat losses. This comprehensive analysis allows for the segmentation of the entire building stock according to the energy class, which serves as the basis for calculating thermal energy demand. The available EPC dataset is used to establish reference consumption values – quantified in kilowatt-hours per square meter – which are then applied to each segment of the building stock to estimate energy consumption, with an accuracy of over 80%. Conclusions remark on the need for similar tools for local decision-makers and the possibility of implementing the research as a thematic layer of an energy digital twin to support energy renovation policies and local Renewable Energy Communities.